[or-cvs] r10097: Start implementing key certificate parsing. Note TODO items (in tor/trunk: . doc src/or)
nickm at seul.org
nickm at seul.org
Wed May 2 21:37:57 UTC 2007
Author: nickm
Date: 2007-05-02 17:37:55 -0400 (Wed, 02 May 2007)
New Revision: 10097
Modified:
tor/trunk/
tor/trunk/doc/TODO
tor/trunk/src/or/or.h
tor/trunk/src/or/routerparse.c
Log:
r12639 at catbus: nickm | 2007-05-02 17:37:49 -0400
Start implementing key certificate parsing. Note TODO items for combined 101/103.
Property changes on: tor/trunk
___________________________________________________________________
svk:merge ticket from /tor/trunk [r12639] on 8246c3cf-6607-4228-993b-4d95d33730f1
Modified: tor/trunk/doc/TODO
===================================================================
--- tor/trunk/doc/TODO 2007-05-02 21:37:53 UTC (rev 10096)
+++ tor/trunk/doc/TODO 2007-05-02 21:37:55 UTC (rev 10097)
@@ -53,13 +53,23 @@
Things we'd like to do in 0.2.0.x:
- Proposals:
- - 101: Voting on the Tor Directory System
+ . 101: Voting on the Tor Directory System
- Prepare ASAP for new voting formats
- Don't flip out with warnings when voting-related URLs are
uploaded/downloaded.
- - Finalize proposal
+ . Finalize proposal
+ - Merge 101 and 103 and dir-spec.txt into a new dir-spec.txt; fork
+ the existing one into dir-spec-v2.txt.
- Get authorities voting
- - Implement parsing for new document formats
+ . Implement parsing for new document formats
+ o Parse key certificates
+ - Parse votes and consensuses
+ - Unit tests for above
+ - Code to manage key certificates
+ - Cache on disk
+ - Download as needed
+ - Serve list as needed.
+ - Avoid double-checking signatures every time we get a vote.
- Code to generate votes
- Code to generate consensus from a list of votes
- Add a signature to a consensus.
@@ -85,6 +95,7 @@
- 108: Base "Stable" Flag on Mean Time Between Failures
- 109: No more than one server per IP address
- 103: Splitting identity key from regularly used signing key
+ - Merge with 101 into a new dir-spec.txt
- 113: Simplifying directory authority administration
- 110: prevent infinite-length circuits (phase one)
- servers should recognize relay_extend cells and pass them
Modified: tor/trunk/src/or/or.h
===================================================================
--- tor/trunk/src/or/or.h 2007-05-02 21:37:53 UTC (rev 10096)
+++ tor/trunk/src/or/or.h 2007-05-02 21:37:55 UTC (rev 10097)
@@ -1300,6 +1300,14 @@
crypto_pk_env_t *onion_key; /**< Current onionskin key. */
} extend_info_t;
+/** DOCDOC */
+typedef struct authority_cert_t {
+ signed_descriptor_t cache_info;
+ crypto_pk_env_t *identity_key;
+ crypto_pk_env_t *signing_key;
+ time_t expires;
+} authority_cert_t;
+
#define CRYPT_PATH_MAGIC 0x70127012u
/** Holds accounting information for a single step in the layered encryption
@@ -3198,5 +3206,11 @@
networkstatus_t *networkstatus_parse_from_string(const char *s);
+void authority_cert_free(authority_cert_t *cert);
+authority_cert_t *authority_cert_parse_from_string(const char *s,
+ char **end_of_string);
+
+
+
#endif
Modified: tor/trunk/src/or/routerparse.c
===================================================================
--- tor/trunk/src/or/routerparse.c 2007-05-02 21:37:53 UTC (rev 10096)
+++ tor/trunk/src/or/routerparse.c 2007-05-02 21:37:55 UTC (rev 10097)
@@ -59,6 +59,19 @@
K_EXTRA_INFO,
K_EXTRA_INFO_DIGEST,
K_CACHES_EXTRA_INFO,
+
+ K_DIR_KEY_CERTIFICATE_VERSION,
+ K_DIR_IDENTITY_KEY,
+ K_DIR_KEY_PUBLISHED,
+ K_DIR_KEY_EXPIRES,
+ K_DIR_KEY_CERTIFICATION,
+
+ K_VOTE_STATUS,
+ K_VALID_UNTIL,
+ K_KNOWN_FLAGS,
+ K_VOTE_DIGEST,
+ K_CONSENSUS_DIGEST,
+
_UNRECOGNIZED,
_ERR,
_EOF,
@@ -91,6 +104,7 @@
typedef enum {
NO_OBJ, /**< No object, ever. */
NEED_OBJ, /**< Object is required. */
+ NEED_KEY_1024, /**< Object is required, and must be a public key of 1024 bits */
NEED_KEY, /**< Object is required, and must be a public key. */
OBJ_OK, /**< Object is optional. */
} obj_syntax;
@@ -108,6 +122,7 @@
#define T(s,t,a,o) { s, t, a, o, 0, INT_MAX }
#define T0N(s,t,a,o) { s, t, a, o, 0, INT_MAX }
#define T1(s,t,a,o) { s, t, a, o, 1, 1 }
+#define T1N(s,t,a,o) { s, t, a, o, 1, INT_MAX }
#define T01(s,t,a,o) { s, t, a, o, 0, 1 }
#define ARGS 0,INT_MAX,0
@@ -121,8 +136,8 @@
T0N("accept", K_ACCEPT, ARGS, NO_OBJ ),
T0N("reject", K_REJECT, ARGS, NO_OBJ ),
T1( "router", K_ROUTER, GE(5), NO_OBJ ),
- T1( "signing-key", K_SIGNING_KEY, NO_ARGS, NEED_KEY ),
- T1( "onion-key", K_ONION_KEY, NO_ARGS, NEED_KEY ),
+ T1( "signing-key", K_SIGNING_KEY, NO_ARGS, NEED_KEY_1024 ),
+ T1( "onion-key", K_ONION_KEY, NO_ARGS, NEED_KEY_1024 ),
T1( "router-signature", K_ROUTER_SIGNATURE, NO_ARGS, NEED_OBJ ),
T1( "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ ),
T0N("opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
@@ -166,7 +181,7 @@
T0N("opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
T1( "contact", K_CONTACT, CONCAT_ARGS, NO_OBJ ),
/* XXXX should dir-signing-key really have ARGS? */
- T1( "dir-signing-key", K_DIR_SIGNING_KEY, ARGS, NEED_KEY ),
+ T1( "dir-signing-key", K_DIR_SIGNING_KEY, ARGS, NEED_KEY_1024 ),
T1( "fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ ),
T1( "network-status-version", K_NETWORK_STATUS_VERSION,
GE(1), NO_OBJ ),
@@ -201,6 +216,82 @@
END_OF_TABLE
};
+#define CERTIFICATE_MEMBERS \
+ T1("dir-key-certificate-version", K_DIR_KEY_CERTIFICATE_VERSION, \
+ GE(1), NO_OBJ ), \
+ T1("dir-identity-key", K_DIR_IDENTITY_KEY, NO_ARGS, NEED_KEY ),\
+ T1("dir-key-published",K_DIR_KEY_PUBLISHED, CONCAT_ARGS, NO_OBJ), \
+ T1("dir-key-expires", K_DIR_KEY_EXPIRES, CONCAT_ARGS, NO_OBJ), \
+ T1("dir-signing-key", K_DIR_SIGNING_KEY, NO_ARGS, NEED_KEY ),\
+ T1("dir-key-certification", K_DIR_KEY_CERTIFICATION, \
+ NO_ARGS, NEED_OBJ),
+
+static token_rule_t dir_key_certificate_table[] = {
+ CERTIFICATE_MEMBERS
+ T1("fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ ),
+ END_OF_TABLE
+};
+
+#if 0
+/* XXXX This stuff is commented out for now so we can avoid warnings about
+ * unused variables. */
+
+static token_rule_t status_vote_table[] = {
+ T1("network-status-version", K_NETWORK_STATUS_VERSION,
+ GE(1), NO_OBJ ),
+ T1("vote-status", K_VOTE_STATUS, GE(1), NO_OBJ ),
+ T1("published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ ),
+ T1("valid-until", K_VALID_UNTIL, CONCAT_ARGS, NO_OBJ ),
+ T1("known-flags", K_KNOWN_FLAGS, CONCAT_ARGS, NO_OBJ ),
+ T( "fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ ),
+
+ CERTIFICATE_MEMBERS
+
+ T0N("opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
+ T1( "contact", K_CONTACT, CONCAT_ARGS, NO_OBJ ),
+ T1( "dir-source", K_DIR_SOURCE, GE(3), NO_OBJ ),
+ T1( "dir-options", K_DIR_OPTIONS, ARGS, NO_OBJ ),
+ T1( "known-flags", K_KNOWN_FLAGS, CONCAT_ARGS, NO_OBJ ),
+ T01("client-versions", K_CLIENT_VERSIONS, CONCAT_ARGS, NO_OBJ ),
+ T01("server-versions", K_SERVER_VERSIONS, CONCAT_ARGS, NO_OBJ ),
+
+ END_OF_TABLE
+};
+
+static token_rule_t status_consensus_table[] = {
+ T1("network-status-version", K_NETWORK_STATUS_VERSION,
+ GE(1), NO_OBJ ),
+ T1("vote-status", K_VOTE_STATUS, GE(1), NO_OBJ ),
+ T1("published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ ),
+ T1("valid-until", K_VALID_UNTIL, CONCAT_ARGS, NO_OBJ ),
+
+ CERTIFICATE_MEMBERS
+
+ T0N("opt", K_OPT, CONCAT_ARGS, OBJ_OK ),
+
+ T1N("dir-source", K_DIR_SOURCE, GE(3), NO_OBJ ),
+ T1N("fingerprint", K_FINGERPRINT, CONCAT_ARGS, NO_OBJ ),
+ T1N("contact", K_CONTACT, CONCAT_ARGS, NO_OBJ ),
+ T1N("vote-digest", K_VOTE_DIGEST, GE(1), NO_OBJ ),
+
+#if 0
+ T1( "dir-options", K_DIR_OPTIONS, ARGS, NO_OBJ ),
+ T1( "known-flags", K_KNOWN_FLAGS, CONCAT_ARGS, NO_OBJ ),
+#endif
+
+ T01("client-versions", K_CLIENT_VERSIONS, CONCAT_ARGS, NO_OBJ ),
+ T01("server-versions", K_SERVER_VERSIONS, CONCAT_ARGS, NO_OBJ ),
+
+ END_OF_TABLE
+};
+
+static token_rule_t vote_footer_token_table[] = {
+ T01("consensus-digest", K_CONSENSUS_DIGEST, EQ(1), NO_OBJ ),
+ T( "directory-signature", K_DIRECTORY_SIGNATURE, GE(2), NEED_OBJ ),
+ END_OF_TABLE
+};
+#endif
+
#undef T
/* static function prototypes */
@@ -285,13 +376,14 @@
router_append_dirobj_signature(char *buf, size_t buf_len, const char *digest,
crypto_pk_env_t *private_key)
{
- char signature[PK_BYTES];
+ char *signature;
int i;
+ signature = tor_malloc(crypto_pk_keysize(private_key));
if (crypto_pk_private_sign(private_key, signature, digest, DIGEST_LEN) < 0) {
log_warn(LD_BUG,"Couldn't sign digest.");
- return -1;
+ goto err;
}
if (strlcat(buf, "-----BEGIN SIGNATURE-----\n", buf_len) >= buf_len)
goto truncated;
@@ -300,15 +392,19 @@
if (base64_encode(buf+i, buf_len-i, signature, 128) < 0) {
log_warn(LD_BUG,"couldn't base64-encode signature");
tor_free(buf);
- return -1;
+ goto err;
}
if (strlcat(buf, "-----END SIGNATURE-----\n", buf_len) >= buf_len)
goto truncated;
+ tor_free(signature);
return 0;
+
truncated:
log_warn(LD_BUG,"tried to exceed string length.");
+ err:
+ tor_free(signature);
return -1;
}
@@ -623,7 +719,7 @@
}
/** Check whether the K_DIRECTORY_SIGNATURE token in <b>tok</b> has a
- * good signature for <b>digest</b>.
+ * good signature for <b>digest</b>. DOCDOC can be another type.
*
* If <b>declared_key</b> is set, the directory has declared what key
* was used to sign it, so we will use that key only if it is an
@@ -641,11 +737,9 @@
crypto_pk_env_t *declared_key,
int check_authority)
{
- char signed_digest[PK_BYTES];
+ char *signed_digest;
crypto_pk_env_t *_pkey = NULL;
- tor_assert(tok->n_args == 1);
-
if (declared_key) {
if (!check_authority || dir_signing_key_is_trusted(declared_key))
_pkey = declared_key;
@@ -661,14 +755,15 @@
return -1;
}
- if (strcmp(tok->object_type, "SIGNATURE") || tok->object_size != 128) {
- log_warn(LD_DIR, "Bad object type or length on directory signature");
+ if (strcmp(tok->object_type, "SIGNATURE")) {
+ log_warn(LD_DIR, "Bad object type on directory signature");
return -1;
}
-
tor_assert(_pkey);
- if (crypto_pk_public_checksig(_pkey, signed_digest, tok->object_body, 128)
+ signed_digest = tor_malloc(tok->object_size);
+ if (crypto_pk_public_checksig(_pkey, signed_digest, tok->object_body,
+ tok->object_size)
!= 20) {
log_warn(LD_DIR, "Error reading directory: invalid signature.");
return -1;
@@ -912,21 +1007,11 @@
tok = find_first_by_keyword(tokens, K_ONION_KEY);
tor_assert(tok);
- if (crypto_pk_keysize(tok->key) != PK_BYTES) {
- log_warn(LD_DIR, "Wrong size on onion key: %d bits!",
- (int)crypto_pk_keysize(tok->key)*8);
- goto err;
- }
router->onion_pkey = tok->key;
tok->key = NULL; /* Prevent free */
tok = find_first_by_keyword(tokens, K_SIGNING_KEY);
tor_assert(tok);
- if (crypto_pk_keysize(tok->key) != PK_BYTES) {
- log_warn(LD_DIR, "Wrong size on identity key: %d bits!",
- (int)crypto_pk_keysize(tok->key)*8);
- goto err;
- }
router->identity_pkey = tok->key;
tok->key = NULL; /* Prevent free */
if (crypto_pk_get_digest(router->identity_pkey,
@@ -1157,6 +1242,124 @@
return extrainfo;
}
+/** DOCDOC */
+void
+authority_cert_free(authority_cert_t *cert)
+{
+ if (!cert)
+ return;
+
+ tor_free(cert->cache_info.signed_descriptor_body);
+ if (cert->signing_key)
+ crypto_free_pk_env(cert->signing_key);
+ if (cert->identity_key)
+ crypto_free_pk_env(cert->identity_key);
+
+ tor_free(cert);
+}
+
+/** DOCDOC */
+authority_cert_t *
+authority_cert_parse_from_string(const char *s, char **end_of_string)
+{
+ authority_cert_t *cert = NULL;
+ smartlist_t *tokens = NULL;
+ char digest[DIGEST_LEN];
+ directory_token_t *tok;
+ char fp_declared[DIGEST_LEN];
+
+ char *eos = strstr(s, "\n-----END SIGNATURE-----\n");
+ size_t len;
+ if (! eos) {
+ log_warn(LD_DIR, "No end-of-signature found on key certificate");
+ return NULL;
+ }
+ eos = strchr(eos+2, '\n');
+ tor_assert(eos);
+ ++eos;
+ len = eos - s;
+
+ tokens = smartlist_create();
+ if (tokenize_string(s, eos, tokens, dir_key_certificate_table) < 0) {
+ log_warn(LD_DIR, "Error tokenizing key certificate");
+ goto err;
+ }
+ if (router_get_hash_impl(s, digest, "dir-key-certificate-version",
+ "\ndir-key-certification") < 0)
+ goto err;
+ tok = smartlist_get(tokens, 0);
+ if (tok->tp != K_DIR_KEY_CERTIFICATE_VERSION || strcmp(tok->args[0], "3")) {
+ log_warn(LD_DIR,
+ "Key certificate does not begin with a recognized version (3).");
+ goto err;
+ }
+
+ cert = tor_malloc_zero(sizeof(authority_cert_t));
+
+ tok = find_first_by_keyword(tokens, K_DIR_SIGNING_KEY);
+ tor_assert(tok && tok->key);
+ cert->signing_key = tok->key;
+ tok->key = NULL;
+
+ tok = find_first_by_keyword(tokens, K_DIR_IDENTITY_KEY);
+ tor_assert(tok && tok->key);
+ cert->identity_key = tok->key;
+ tok->key = NULL;
+
+ tok = find_first_by_keyword(tokens, K_FINGERPRINT);
+ tor_assert(tok && tok->n_args);
+ if (base16_decode(fp_declared, DIGEST_LEN, tok->args[0],
+ strlen(tok->args[0]))) {
+ log_warn(LD_DIR, "Couldn't decode key certificate fingerprint %s",
+ escaped(tok->args[0]));
+ goto err;
+ }
+
+ if (crypto_pk_get_digest(cert->identity_key,
+ cert->cache_info.identity_digest))
+ goto err;
+
+ if (memcmp(cert->cache_info.identity_digest, fp_declared, DIGEST_LEN)) {
+ log_warn(LD_DIR, "Digest of certificate key didn't match declared "
+ "fingerprint");
+ goto err;
+ }
+
+ tok = find_first_by_keyword(tokens, K_DIR_KEY_PUBLISHED);
+ tor_assert(tok);
+ if (parse_iso_time(tok->args[0], &cert->cache_info.published_on) < 0) {
+ goto err;
+ }
+ tok = find_first_by_keyword(tokens, K_DIR_KEY_EXPIRES);
+ tor_assert(tok);
+ if (parse_iso_time(tok->args[0], &cert->expires) < 0) {
+ goto err;
+ }
+
+ tok = smartlist_get(tokens, smartlist_len(tokens)-1);
+ if (tok->tp != K_DIR_KEY_CERTIFICATION) {
+ log_warn(LD_DIR, "Certificate didn't end with dir-key-certification.");
+ goto err;
+ }
+
+ /* XXXXX This doesn't check whether the key is an authority. IS that what we
+ * want? */
+ if (check_directory_signature(digest, tok, NULL, cert->identity_key, 0)) {
+ goto err;
+ }
+
+ cert->cache_info.signed_descriptor_len = len;
+ cert->cache_info.signed_descriptor_body = tor_malloc(len+1);
+ memcpy(cert->cache_info.signed_descriptor_body, s, len);
+ cert->cache_info.signed_descriptor_body[len] = 0;
+ cert->cache_info.saved_location = SAVED_NOWHERE;
+ *end_of_string = eos;
+ return cert;
+ err:
+ authority_cert_free(cert);
+ return NULL;
+}
+
/** Helper: given a string <b>s</b>, return the start of the next router-status
* object (starting with "r " at the start of a line). If none is found,
* return the start of the next directory signature. If none is found, return
@@ -1841,10 +2044,16 @@
RET_ERR(ebuf);
}
break;
+ case NEED_KEY_1024:
+ if (tok->key && crypto_pk_keysize(tok->key) != PK_BYTES) {
+ tor_snprintf(ebuf, sizeof(ebuf), "Wrong size on key for %s: %d bits",
+ kwd, (int)crypto_pk_keysize(tok->key));
+ RET_ERR(ebuf);
+ }
+ /* fall through */
case NEED_KEY:
if (!tok->key) {
tor_snprintf(ebuf, sizeof(ebuf), "Missing public key for %s", kwd);
- RET_ERR(ebuf);
}
break;
case OBJ_OK:
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